College of Plant Protection , Agricultural University of Hebei , Baoding 071001 , PR China.
Department of Entomology and Nematology and UCD Comprehensive Cancer Center , University of California , Davis , California 95616 , United States.
J Agric Food Chem. 2018 Oct 31;66(43):11284-11290. doi: 10.1021/acs.jafc.8b04521. Epub 2018 Oct 17.
3-Phenoxybenzoic acid (3-PBA) is a human urinary metabolite of many pyrethroid insecticides and can be used as a biomarker to monitor human exposure to these pesticides. A rapid and sensitive direct competitive fluorescence enzyme immunoassay (dc-FEIA) for detecting 3-PBA on the basis of a nanobody (Nb)-alkaline phosphatase (AP) fusion protein was developed. The anti-3-PBA Nb-AP fusion protein was expressed and purified. The 50% inhibitory concentration (IC) and linear range of dc-FEIA were 0.082 and 0.015-0.447 ng/mL, respectively, with a detection limit of 0.011 ng/mL. The IC of dc-FEIA was improved by nearly ten times compared with those of one-step and three-step direct competitive enzyme-linked immunosorbent assay (dc-ELISA). Spiked urine samples were detected by both dc-FEIA and liquid chromatography-mass spectrometry (LC-MS), and the results showed good consistency between the two analysis methods, indicating the reliability of dc-FEIA based on the Nb-AP fusion protein for detecting 3-PBA in urine.
3-苯氧基苯甲酸（3-PBA）是许多拟除虫菊酯类杀虫剂在人体尿液中的代谢物，可用作监测人体接触这些农药的生物标志物。基于纳米抗体（Nb）-碱性磷酸酶（AP）融合蛋白，建立了一种快速灵敏的直接竞争荧光酶免疫分析（dc-FEIA）方法来检测 3-PBA。表达并纯化了抗 3-PBA Nb-AP 融合蛋白。dc-FEIA 的 50%抑制浓度（IC）和线性范围分别为 0.082 和 0.015-0.447ng/mL，检测限为 0.011ng/mL。与一步法和三步法直接竞争酶联免疫吸附测定（dc-ELISA）相比，dc-FEIA 的 IC 提高了近十倍。用 dc-FEIA 和液相色谱-质谱（LC-MS）检测了加标尿液样品，两种分析方法的结果具有良好的一致性，表明基于 Nb-AP 融合蛋白的 dc-FEIA 用于检测尿液中 3-PBA 的可靠性。
